Just contact MS, if you installed the same Windows version as the one that came with your machine and explain that you already own a license you will (most surely) get activation for free.
When you say restore disks do you mean:
a. the SystemCD + 2 Recovery CDs you got from Acer
b. your backup DVD/CDs
Re a. should work even with only 1 partition (which should be FAT32 as indicated by DarthAcer
Note: this is fromTM8106 experience (SystemCD rev.6 for TM8100...